Symptoms

Microsoft has released a patch that eliminates a security vulnerability in Internet Information Server (IIS). This vulnerability could enable a malicious user to send malformed URLs that prevent a Web server from being able to respond to requests for Web pages, FTP services, or any other services that are provided by IIS.

NOTE: This vulnerability does not provide the opportunity to compromise any data on the server or compromise any administrative privileges on the server. You can place the server back in service by restarting the IIS service.

You can find additional information about this vulnerability and the patch at the following Microsoft Web site:

Cause

The vulnerability is caused by a problem in Windows NT 4.0 that causes IIS to mishandle a particular type of invalid URL under certain conditions.

Resolution

Windows NT 4.0

To resolve this problem, obtain the individual package referenced below or obtain the Windows NT 4.0 Security Rollup Package. For more information on the SRP, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.The English version of this fix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Microsoft Windows NT Server version 4.0, Terminal Server Edition

To resolve this problem, obtain the Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package (SRP). For more information about the SRP, click the following article number to view the article in the Microsoft Knowledge Base: